OD调查的误区——“元(数理)交通规划论”研究之一

Misconception of OD Investigations

OD调查的目的是利用调查所得的OD数据对样本总体的均值作出统计推断。提出了两个指标来测度这种推断的精度和可靠性 ,并在此基础上 ,依据弱大数定理 ,深入讨论了OD抽样的样本容量问题。然后 ,通过实例的考查 ,间接地估算了样本总体的相对标准差。研究的结论指出 :在一般情况下 ,仅作一天OD调查 ,所得的OD数据是不可用的。

The purpose of OD investigations is to make statistical estimation of the average value of the samples based on the OD data obtained.In this paper, two indexes are proposed to measure the precision and reliability of the estimation, and the problem of the samples capacity is thoroughly discussed based on weak large number theorem. Then the relative standard difference is estimated indirectly from the research of the examples. The research result shows that, in the common cases,the OD data which are based on one day investigations are to no avail.